This project is designed to investigate the functional relationship between the loading characteristics of total joint components and remodeling of the supporting trabecular bone. The specific objective is to identify the optimum stress parameters which promote positive trabecular bone remodeling. Utilizing implantable load transmitting devices, the dynamic response of canine metaphyseal trabecular bone to controlled loading, stimuli will be measured. The phases of the study will include: 1. Fabrication and calibration of the implanted load delivery system; 2. Assesment and documentation of all control variables and measurements; 3. Measurement and analysis of trabecular bone remodeling responses to experimentally controlled stress fields. The experimental variables will be measured using the following techniques: computed axial tomography, nuclear imaging, histologic section and fluorescence, mechanical materials testing, ash weight determination.